• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.10
• /
• pp.30-40
• /
• 2013

In this study the method based on flux linkage in cell was introduced in calculation of eddy currents by cell method. According to this method eddy current distribution and the loss can be evaluated and since the shielding effectiveness by flux cancelation of eddy current can be analyzed, this method is applicable to design of conductive shield. And also the formula of shielding factor were so deduced as to be applicable to finite-width infinite-length shielding sheets and infinite-length underground cable shield. These formula are adaptable to magnetic materials as well as conductive materials. As the results of calculation in model shields are follows. In case of finite-width infinite-length shielding sheet, shielding effectiveness increases with increasing of conductivity. In case of infinite-length underground cable shield, the effectiveness become higher with increasing of permeability. Especially the effectiveness is very high in materials with both high conductivity and permeability in underground cable shield.

• Journal of the Korean Data and Information Science Society
• /
• v.26 no.3
• /
• pp.653-659
• /
• 2015

The Pythagorean formula for baseball postulated by James (1982) indicates the winning percentage as a function of runs scored and runs allowed. However sometimes, the Pythagorean formula gives a less accurate estimate of winning percentage. We use the records of team vs team historic win loss records of Korean professional baseball clubs season from 2005 and 2014. Using assumption that the difference between winning percentage and pythagorean expectation are affected by unusual distribution of runs scored and allowed, we suppose that difference depends on mean, standard deviation, and coefficient of variation of runs scored per game and runs allowed per game, respectively. In conclusion, the discrepancy is mainly related to the coefficient of variation and standard deviation for run allowed per game regardless of run scored per game.

• Herbal Formula Science
• /
• v.17 no.1
• /
• pp.99-111
• /
• 2009

Rheumatoid arthritis is characterized by focal loss of cartilage due to an up-regulation of inflammatory pathways, which produce pro-inflammatory mediators, such as interleukin-1(IL-1), tumour necrosis factor alpha($TNF-\alpha$), prostaglantin, and nitric oxide(NO). We investigated the anti-arthritic effects of water extracts from Pellodendri cortex and Atractylodis rhizoma in vitro and in vivo. Each extract suppressed the production of inflammatory mediators(NO, $IL-1\beta$, $TNF-\alpha$, and prostaglandin $E_2$) and the expression of inducible NO synthase and cyclooxygenase-2 in lipopolysaccharide-stimulated macrophages in a dose-dependent manner. These suppressive effects were synergistically increased by their combination. The same results were also observed in the rat osteoblast sarcoma cell line ROS17/2.8 stimulated with $IL-1\beta$, $IFN-\gamma,$ and $TNF-\alpha$. Moreover, the combination of these water extracts significantly suppressed collagen-induced mouse arthritis. These results suggest that the combination of water-extractable components of Pellodendri cortex and Atractylodis rhizoma may be useful for therapeutic drugs against rheumatoid arthritis, probably by suppressing the production of inflammatory mediators.

• Herbal Formula Science
• /
• v.19 no.1
• /
• pp.91-102
• /
• 2011

Objectives : This report describes 48 prescriptions related to the use of Herba Menthae main blended from Dongeuibogam. The following conclusions were drawn through investigations on the prescriptions that use Herba Menthae as a key component. Prescriptions that Herba Menthae was taken as a monarch drug are utilized for 15 therapeutic purposes, for example, wind stroke, throat disease, nose disease, head disease and tooth disease. In particular, 12.5% of prescriptions appear in the chapter of each wind stroke, throat disease, nose disease. Methods : Prescriptions that utilize Herba Menthae as the main ingredient are used in the treatment of urticaria, hemoptysis-hematemesis, loss of consciousness due to wind stroke and they are also used for treating 41 different types of disease. Herba Menthae is used for pathogenic factors such as wind and heat. Results : The dosage of Herba Menthae is 0.15pun(about 0.06g) to 4don(about 14g), however 5pun(about 1.88g) has been taken the most for clinical application. Conclusions : Gamgiltang, Piryongbanggamgiltang and Hoichunyanggyeoksan are the most useful base prescriptions which use the Herba Menthae as the main ingredient.

• Herbal Formula Science
• /
• v.18 no.2
• /
• pp.183-199
• /
• 2010

Rheumatoid arthritis is characterized by the focal loss of cartilage due to an up-regulation of inflammatory pathways, which produce inflammatory mediators, such as interleukin-1beta(IL-$1{\beta}$), IL-6, tumour necrosis factor alpha(TNF-$\alpha$), prostaglandin, and nitric oxide(NO). We investigated the anti-arthritic effects of water extract from FLOS LONICERAE(FLWE) in vitro and in vivo. Extract inhibited the production of inflammatory mediators(NO, IL-$1{\beta}$, TNF-$\alpha$, and prostaglandin $E_2$) and the expression of inducible NO synthase(iNOS) and cyclooxygenase-2(COX-2) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in a dose-dependent manner. FLWE also inhibited TNF-$\alpha$, IL-$1{\beta}$, IL-6, and $PGE_2$ production as well as COX activity in collagen-induced mouse arthritis. Moreover, FLWE significantly suppressed collagen-induced mouse arthritis. These results suggest that FLOS LONICERAE may be useful for therapy against inflammatory immune diseases and rheumatoid arthritis, probably by suppressing the production of inflammatory mediators.

• Journal of the Korean Society of Industry Convergence
• /
• v.24 no.6_2
• /
• pp.819-825
• /
• 2021

In the industry, the use of lightweight bearings is increasing to minimize motor power loss, and in particular, the application of next-generation systems such as robots and drones is increasing. Bearing manufacturers are producing lightweight bearings by changing the bearing material, but related researches is insufficient. In this paper, life test and structural analysis were performed for lightweight bearings, and shape parameters and scale parameters were derived based on the life test results. It was confirmed that the shape parameter was 2.52 and the scale parameter was 164 hours. As a result of calculating the dynamic load rating based on the B₁₀ life, it was confirmed that the dynamic load rating of the lightweight bearing was 7% compared to the formula suggested by ISO 281. The reason is that the material of the retainer, which is a major failure part, is a polyamide 66 series that reacts sensitively to heat, so It is judged to show a lot of difference from the ISO 281 calculation formula.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.5
• /
• pp.407-415
• /
• 2021

The performance of satellite parts must be verified under the space orbit environment before the launch. This paper develops a model formula considering the thermal environment such as conduction, radiation, heat loss and internal heating between satellite parts and a small thermal vacuum chamber for thermal vacuum tests. System identification is carried out using test data from 20 recent thermal vacuum tests conducted by the Korea Aerospace Research Institute. It is verified that the model formula and the identification results are valid, except when the heating of the functional test of the test specimen is not constant.

• Nuclear Engineering and Technology
• /
• v.13 no.3
• /
• pp.121-129
• /
• 1981

Three most outstanding maximum flow rate formulas are identified from many existing models. Outlines of the three limiting mass flow rate models are given along with computational procedures to estimate approximate amount of fission products released from a containment to environment for a given characteristic hole size for containment-isolation failure and containment pressure and temperature under a loss of coolant accident. Sample calculations are performed using the critical ideal gas flow rate model and the Moody's graphs for the maximum two-phase flow rates, and the results are compared with the values obtained from the mass leakage rate formula of CONTEMPT-LT code for converging nozzle and sonic flow. It is shown that the critical ideal gas flow rate formula gives almost comparable results as one can obtain from the Moody's model. It is also found that a more conservative approach to estimate leakage rate from a containment under a LOCA is to use the maximum ideal gas flow rate equation rather than tile mass leakage rate formula of CONTEMPT-LT.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.6
• /
• pp.989-999
• /
• 2017

In this study, hydraulic experimental studies were conducted to estimate the empirical formulas of loss coefficient, which is necessary to calculate the energy loss occurred in the dividing channel junction of sewer system. The experimental apparatus was consisted of two outflow conduit with a $90^{\circ}$ angle to the inlet conduit, and the pressure and velocity heads are measured to analyze the energy losses in the branch. The measurements of the hydraulic grade line show that the hydraulic grade line was steeply descended at the dividing point due to the head loss, and the decreasing amount of velocity head increased with the increase of flowrate ratio. The head loss exponentially increased in the outlet with larger runoff as the increase of flowrate ratio and Froude number, and the head loss coefficient also increased. On the other hands, the head loss coefficients decreased in the outlet with smaller runoff as the increase of the flowrate ratio and Froude number. Using the experimental results, the empirical formulas of loss coefficient was suggested for each outlet, and the error of empirical formula was 3.91 and 5.19%, respectively. Furthermore, the total head loss coefficient calculated by the two empirical formulas was compared with the experimental results, and the error was 3.62%.

• Journal of Korean Society on Water Environment
• /
• v.36 no.5
• /
• pp.385-391
• /
• 2020

Soil loss is a serious problem frequently caused by local torrential rainfalls due to climate change. In particular, soil loss is occurring in agricultural areas rather than urban areas, and many pollutants are introduced into rivers, causing environmental problems. To reduce soil loss, the Ministry of Environment has designated and managed non-point source management areas. The Jaun-district in Hongcheon-gun, which was designed as a non-point pollution source management area in Gangwon-do, is located in the upper stream of Soyang Lake. Most of the agricultural fields are composed of highland agriculture fields. The highland agricultural fields in the Jaun-district are also composed of large-scale farming areas, and the ditches located near the agricultural fields have been illegally used for farmland. Therefore, the local government in Hongcheon-gun is conducting a project to restore the ditches occupied by agricultural fields. However, an analysis of the amount of soil loss that can be reduced by the restoration of the ditches has not been conducted yet. Thus, the purpose of this study was to analyze the effect of reducing the soil loss from the restoration of the ditches used as agricultural fields in the Jaun-district. The SATEEC L Module was used to analyze the reduction in soil loss by ditch restoration. The SATEEC L Module was constructed to estimate the LS factor using Moore and Burch's method after calculating the slope length using the digital elevation model and the maximum allowable slope length. The LS factor and the USLE formula were used to estimate the amount of soil loss that could be reduced by ditch restoration. The analysis showed that the ditch restoration could reduce about 16.6% of the soil loss in the Jaun-district. The results of this study will contribute to the study of methods to reduce soil loss in non-point pollution management areas.